The invention relates to an apparatus for the production of warps, in particular for cloth designs, in multi-color weaving in which the differently colored yarns are wound successively and side-by-side on a winding body such as a drum, and the yarns pass through thread crossing means during the winding operation. After the threads have been wound in a preselected number of loops around the winding element, the wound threads will be cut at their crossing points into separate warp lengths.
Such machines for the production of short warps serve the purpose of enabling a short yarn to be warped with but one bobbin per color, whereby there is a considerable saving in working time and material. The production of groups of yarns with the yarn colors changing over predetermined widths of the whole group allows the production of cloth designs to be carried out rationally, thus facilitating the production of samples.
In the case of one known kind of short warp warping frames (U.S. Pat. No. 3,247,568), the yarn winding guide is movable along the peripheral contour of the winding device at right angles to the direction of movement of the winding surface, whereas the carrier for the beam is stationary relative to the winding device. Moreover, the winding device is built up from at least two redirecting rollers which are arranged in spaced apart relationship and the relative spacing apart of which is adjustable. The warping machine is, moreover, provided with a transverse feeding belt operatively mounted on each one of a plurality of longitudinal peripheral members, said transverse feeding belts being movable in axial direction of the drum. Furthermore, the warping machine has a threaded spindle axially mounted in each one of the pair of drums, and it comprises coupling means mounted on the spindle and connected to the transverse feeding belts for moving the latter in the transverse feed direction of the wound thread. After all, the warping machine includes thread crossing means operatively mounted in said machine between the two winding elements.
In the case of another machine for producing warps (GB No. 1,323,320), there is used as a warping frame a winding former which is in the form of a drum with a conically ascending initial portion. The thread winding guide for the threads to be wound is arranged displaceably along the drum. Moreover, there is arranged over the circumference of the drum a flexible metal strip or separator strip which serves for the formation of leases or crossings, for instance, once at the beginning and once at the end of each section of threads.
The drum with the cone portion enables the winding of the group of yarns to be effected in lengths, whereby the winding can be continued without interruption from the start of the first length up to the end of the last length. The yarns are wound tightly after each finishing of a length up to the start of the next length. In doing so, there can be undertaken at least shortly before the finishing of a length, a severance between the preceeding windings and the winding or windings still to be produced. In the case of the known machine, the conical drum as has a relatively large diameter of about 2 to 2.5 m. The construction of the known device is complicated and expensive. The control of the advance of the lease rods and the apparatus for feeding the yarns to the drum is performed by separate driving means, the operation of which is harmonized to one another. The handling of the known device is involved. The equipment for the production of warps is relatively inefficient.